This video is brought to you by spore'ln quality, integrity and tradition. Alright, I want to start this off by giving a disclaimer do not under any circumstances, try what I'm about to do. I do not want anybody to get any ideas from what I'm about to do. I'm doing an experiment, I was in a controlled environment.

I was very safe about what I was doing. Do not try to be an engineer. Do not try to you know, redesign things. If you don't know what you're doing I'm an idiot, I clearly don't know what I'm doing, but I'm just kind of making some assumptions and some guesses here.

Okay, to give some context, I'm gon na be doing an experiment here, where I take a are 290 refrigerator, completely operating actually brand new. That long story short the customer asked me to dispose of, but I decided to use it to do some experimenting. Stefan, I am going to be taking this our 290 refrigerant. What I do is I remove all the our 290 from it.

I pull a proper evacuation, make sure that it passes a decay test and the video is gon na start with me. Weighing in new are 290, I'm gon na weigh in the factory charge, and then the video will pretty much lay out the rest of what I'm gon na do. Okay, so the videos gon na start off with me weighing in the brand new, are 290 charge and then, after that, we will go through the experiment and try a few things. Okay, all right, so we're getting ready to charge this guy.

This unit takes a hundred and thirteen grams, and one thing that I will say is you know: kind of crappy is most scales, won't read and increments pass like 105 110. They don't like this. One won't say 113, so you kind of got to figure it out. I've already purged right here, so we've purged that we're gon na zero our scale and we're gon na go ahead and charge it in the system still in a vacuum.

We're charging it on the high side. So it should take quite a bit and in fact we actually need to go ahead and purge there. We go just to get the air out we're good okay. So now we need to go ahead and zero it out and we're gon na go ahead and open.

This guy up, actually, I should have yeah we're good, okay, make sure it's zeroed and then we're gon na open this guy up and we're going to a hundred and thirteen grams of our 290. I'm pretty sure it'll pull it all in because we're in such a good vacuum liquid, our 290. So I should pull it in pretty good go and let that happen. I still don't have probes on here, we'll put those on here in just a minute.

We just want to get this guy charged up and then we're gon na take some vitals and see how long it takes to come down to temp with our 290 and then we'll go ahead and remove the charge vacuum it down again. Make sure we have a popper evacuation and then we'll go ahead and put 134a in it and then do the test to see you know how well it works with our 290 vs. 134 eh, all right. It's getting dark outside, but my unit is starts in a defrost, so I'm gon na pop it out a defrost right now and we're gon na fire.

It up. You know just fired up. I'm gon na start the stopwatch on my wrist. Okay, what we're gon na do this unit has the factory charge in it brand new.

I waited in from a proper vacuum, like you guys saw I'm monitoring, evaporator superheat. I am moderating discharge temperature, liquid line temperature outdoor air and then obviously, the pressures we're gon na see how long this unit takes to come down to temperature and at what from the factory, we're gon na benchmark the settings. When we figure out what kind of an evaporator, TD and condenser TD that they run with our 290 and then we're gon na mimic, those numbers when I put 134a in so essentially if this thing runs with a you know, 15 degree, condenser TD, then we're gon Na mimic that with 134a or attempt to and the same thing for the evaporator TD and then we're gon na see we're gon na time the pull down time from startup my box is, I have had the doors open for quite a while, so my box is 57 degrees inside right now so we'll mimic those tomorrow when we pull down with 134a all right, we are at 22 minutes and the unit has satisfied. So, let's just call it 20 minutes, yep, satisfied and happy all right.

So I let this thing run overnight. Came back out it's down to temperature again, this has our 290 in it and with the factory charge, our numbers are not crazy. I mean I have no set idea as to what the numbers would be. I've not talked to the manufacturer, so just off of the factory charge, that's weighed in you can see that as my expansion valve opens and closes my subcooling changes, which would be expected because this system does not have a receiver.

So it's using the condenser as the storage device, so the refrigerant backs up in the condenser and then leaves the condenser depending on how much the expansion valve opens and closes. So that seems good. I set my benchmark. Temperatures based off of the evaporator and condenser TD of the unit operating right now, my box temp.

I just opened a door to bring the box temp up a little bit because it was just about to satisfy, but it's coming down in temperature. This is what we're seeing we're seeing pretty normal. The expansion valve is doing its job, adjusting the superheat it's trying to maintain about 10 degrees superheat, and when I open the door it you know changed and all that but sub coin I've seen it anywhere from 10 to 15 degrees, yeah everything's, looking good. So the next part of this step, so this is a fully operating r2 90 system.

I'm gon na take some thermal imaging videos of the condenser and of the evaporator and then we're gon na get some current draw of the unit and then we'll continue on with the test. We're going to go to thermal image mode right now, and what we have here is our condenser coil doesn't look like anything's too abnormal. It's the evaporator, nothing crazy-looking! So yeah, I don't see any problems with this and everything seems to be operating properly. Last thing I took the cover off the condenser, so we can get a better thermal image view and I've got the redfish 550 meter on there and I'm measuring the total power usage of this unit.

I've removed the r2 90 charge and I'm sweeping the system with nitrogen to agitate the compressor a few times try to get any of our 290 vapor out of the oil. This way, I am never theoretically, as long as that, nitrogen is dry and has no moisture. I'm never introducing moisture into this system and I'm simply just sweeping with nitrogen from the r2 90. So basically, I vented the r2 90 charge, which is totally legit and then left a slight amount of pressure in there hooked up the nitrogen purged it as I was screwing it on vented it, and now I'm just purging with nitrogen.

So now, there's theoretically should be nothing but nitrogen in the system, and now we're gon na do an evacuation on it. Yeah you can see we're like coming down at a funky angle and what you'll notice. So you see my microns, I'm only pulling from one side at this moment, but what will happen is I move this over here. I'm only pulling from one side at this moment, but you'll notice that what happens when I shame to shake the compressor.

That number jumps, because the nitrogen and the refrigerant now is boiling out of the oil. So what we're gon na do? We can do some things to speed that up. You can just continue to agitate it. You can heat up the compressor with a crankcase heater with a heating blanket, or something like that.

I happen to have a heat gun he'd. Be careful though, because this has flammable refrigerant in it. Now it's just vapor, but it still might have pockets. So I have a heat gun on there and I bet you anything.

We see a spike in a minute once it heats up oil, so right now we're at 5300 microns, I'm very carefully heating it up with a heat gun, making sure it's not gon na melt. Anything else - and I bet you once that compressor gets hot enough you'll start seeing that micron reading go up, it'll, probably reflected in the graph. More than likely I'll show you guys when it pops up. There was a little bump because trapped vapor, refrigerant and nitrogen is popping out of the oil, but it's coming down.

Now, I'm only pulling from one side, I'm gon na go ahead and open up this other side, because I want to speed it up. It is gon na make some for some funky numbers with a vacuum. You notice now that I opened that up. It's gon na start dropping really fast, and that has a lot to do with with the micron gauge being so close to where the hose is connected.

So another thing I didn't do is I didn't open the gas ballast, but it's okay, so you'll see a drop now and yeah all right. I'm gon na show something real quick, so you see little spikes and that's all the vapor boiling out of the refrigerant, the nitrogen and the refer amines, sorry out of the oil, the nitrogen and the refrigerant. But if we come up here - and we look at this - so I opened this core removal tool up, so it was pulling from both sides but to get a true reading. I need to close it, but this is going to just show you how important it is to have your micron gauge hooked up to the right side.

So, even though it was reading really low once i've valved it off and now it's only getting a true reading from the other side. Look at how high it's climbing, because that wasn't an accurate reading. The reason why the micron gauge was so low was because it was connected too close to the hose and it was actually getting more pull from the vacuum pump, then the actual true reading of the system. Alright, this is my final decay test.

I'm gon na go ahead and call it at this. It's it's slowly rising, but I think we're gon na be okay, so I'm gon na let it decay for a few more minutes and just make sure that we don't climb too high and then we're gon na go ahead and put the 134a in the system. Alright, I don't think it's gon na get too much better than this. I don't want to spend too much time on this guy.

It's slowly rising, but I guess I should technically make it. The decay test continue to catch us. Let's see what we're doing here. So decay rate is 0.6 point a it's kind of bouncing around dropping down 0.3.

You know I've kind of wonder if there's moisture in the nitrogen or the refrigerant who knows, but I think this is about as good as just gon na get mind you we are at 378 microns, so I mean technically from the looks of it. It kind of looks like it's still got some kind of non-condensibles or moisture in there, but um, I'm not an expert, but I mean it's just a gradual rise and it kind of looks like it's tapering off to me. So we're gon na call this and go ed and charge this guy with 134. You know so we have a clean dry system, everything's zeroed out I've purged all the way up to here, and I slowly had it cracked.

While I was putting it on so that way, it's not getting any air into the system, we're gon na zero out and we're gon na start with the factory charge of a hundred and thirteen grams that the R to 90 hat we'll put a hundred and thirteen Grams of 134a and then we'll see how the system operates and then we'll go from there. We got a zero this guy out, though, because it's kind of bouncing around okay, so we're charging on the high side. Let's start see it's ten increments of ten, so you're not going to see the whole hundred and thirteen again. 100 110 we're gon na have to go 100 and 20 and stop because it's the increments that it does it in so we're at 120 grams.

We're gon na go ahead and start this guy up and see what happens yeah. I can go ahead and take off the mic on gauge systems under pressure. Now that way we didn't introduce any unwanted, moisture or air into the system. I'm gon na put this guy on here, alright, so this is kind of bouncing around, but I went ahead and moved it over to the suction line, so it still has the measured refrigerant we put in there.

Our box temp right now is 47 degrees. Let's go through our numbers, it's been running for about two minutes, so outdoor ambient 68 superheat is extremely high. Sub cooling is non-existent, suction moon and we need to go ahead and set some metrics and come up with. I need to input the evaporator temperature or the evaporator TD, like we had on the other one, so I'm gon na do that real, quick, okay, I've got my targets in there we were running a 30 degree, evaporator TD and about a 25 degree condenser tdys, give Or take a little bit there, so that's what we're trying to mimic right now, but obviously we have no sub cooling.

So what that means is: is that we're feeding vapour to our expansion valve, so we have to get that sub cooling number up. I'm gon na aim for about 10 degrees sub cooling in hopes that it brings my superheat down to so we're at about 120 110 grams. So we're just going to add a little bit more and see what we have to add to get our numbers about where they need to be. Alright, it's been a few minutes.

I've added some refrigerant, I'm currently at 330 grams, so mind you, I've gone way over the recommended amount of our 290 of refrigerant for the system, and that is just trying to get this thing to have some sub cooling so currently, where I'm at right. Now. We currently have a 15 degree, condenser TD, we're aiming for a little bit higher and we have an 11 degree evaporator today. We're definitely aiming for higher on that one.

So let's go ahead and go back on over to these numbers and look and see my box. Temp is 41 degrees all right. Our air temp is about 68 degrees, but look at I. I still have point five degrees, subcooling one degree superheat, so we're flooding back to our compressor right now, but the problem is with that lowest sub cooling we're still likely not feeding liquid refrigerant, we're still feeding some vapor to that expansion valve okay and look at our Targets based off of our condenser and evaporator TD from the operating our 290 system were way above our numbers on our targets.

Now this is kind of getting a little bit closer to what I would expect a or Malay operating r134a system. As far as the pressures go, but I'm trying to look at temperatures and the saturation temperatures and my subcooling number and my super heat number - you know everything's kind of out of whack here. If you look at this - and this in my opinion, is because this system was not designed for r134a, if you pay, attention are 290 condenser. If you look at a comparable r134a condenser, the amount of heat rejection capabilities that that condenser has is a lot bigger.

The condenser tubes are a lot smaller. This is, this, isn't even quarter inch. I don't think I think this is something smaller than quarter inch and look at it's just a single. Actually, it's only two passes through the condenser, but you know the the condenser smaller the evaporator, smaller, the compressor smaller so by putting 134a in the system.

In my opinion, it's not working alright and you know - yes, I'm sure it. We are getting some cooling and it is cooling, but it's not right and in my opinion, it's not safe all right. We are not the engineers that made this box. In my opinion, we can't go just dumping refrigerant into this, just because we think that someone on Facebook - or something like that, told us that yeah you can take out our 290 input.

134 aan. Alright, the simple fact that we had to put in more than double the amount of the manufacturer's suggested refrigerant with r134a alone sounds like a safety issue to me. I could only imagine in the summertime, what's gon na happen when they get a really hot kitchen, now granted this units not meant to operate in the outdoors, but this, in my opinion, is proving my point that you cannot put 134a safely in an r2 90 system. Yes, you can just keep adding gas and it might work, but is it right? No, not, in my opinion, I'm going to keep this test going and we're gon na keep these numbers going and see what we can get to all right.

We are at 520 grams. Now is how much I've had to add to get my sub cooling close, and I don't want to overshoot my target so I'm currently at 9 degrees. It's kind of bouncing around mind you that sub cooling number is going to change as the expansion valve opens and closes one degree of evaporator superheat. That is not compressor supreme.

My compressor is ice-cold right now, because we are flooding refrigerant back to it. So the refrigerant, the evaporator, in my opinion, is not big enough in the expansion table is not sized correctly to boil off all the refrigerant needed to give us the sub coin. I mean it's just it's just a hot mess. This whole thing: it's never.

I mean you're, never gon na. It's just not kind of work right. Alright, so I'm not gon na add any more refrigerant, we're at nine point, eight degrees, subcooling and we're watching the system. Now, just looking at the pressures, it doesn't look horrendous, but I don't I'm not so concerned about the pressures on looking at the evaporator temperatures and looking at the performance.

Looking at the sub cooling, look at my evaporator super heat to low. Let's look at our condenser TVs right now, it's going over here. My box, temp, is at 41 degrees. Condenser TD is 14 degrees.

Evaporator TV has eight degrees, so nowhere near the TDS of the are 290 and the condenser TD. Remember that's going to be your efficiency in a nutshell, because, where we that's the ability to reject all that heat out of the condenser with the TD that it was with the our 290 and then the heat transfer capability with the our 290 on the evaporator TD. So if we can't match those numbers, the efficiency is going down the drain. And again I am NOT a scientist guys, I'm just a dumb guy.

That just is just working this out. I don't know all the super technical, crazy terms or anything, but I mean this to me just adds up that it doesn't work again, I'm still, in my opinion, proving that this is not a safe and good practice to do. I'm gon na call this tail or this. You know this tested.

It's it's. It's failed it's. This is not working. It's not safe.

Do not try. This absolutely do not try this. I am in a controlled environment and this refrigerator I mean you with your your tempting fate. What is the big deal about using 134a? I mean our 290.

It's really not that big of a deal don't be afraid of it. The system was designed for it. Now. I'm sure there's gon na be people saying well, you should used r22 or whatever.

The reason why I use 134a was because the majority of the people there on the Facebook groups and commenting say that they drop in 134a or they heard you can drop in 1:30. For a you know, once you remove the are 290, and no you can't this is not proven. This is not safe. Look at the original factory charge was a hundred and thirteen grams of our 290 and I have put 510 grams to get myself somewhat close to the sub cooling number that I had and but look at my superheat when I do that, I mean this is just This is not good, do not do it.

Look at our condenser here so pretty much. The same view same color scheme to me doesn't look like it looks like this. Condenser is just not being able to reject the heat. It's kind of hard to exactly tell what's going on here I mean I know that we're overloading this condenser with refrigerant right now, all right! Last but not least, let's go ahead and look at our power consumption on this bad boy.

Let me get this guy back in here and 0.40 kilowatts 5.26 amps. This thing is still at 48 degrees and I am still at 24 minutes. So this thing isn't even dropping intent, barely so alright. This just concludes this just isn't: gon na work, I'm gon na leave it running just for giggles.

Let it run for a couple days and see what happens but yeah um. It's not working okay, so the experiment was simply to take our 290 out of the equation. Put 134 a in the system and see what would happen and exactly what I expected to happen happened. It doesn't work, okay, sure you can remove some refrigerant and you will get some cooling, I'm sure in some way or another.

You can make it work, but it will not be right and in my opinion it will be dangerous. Okay. The reason why I think it's dangerous is because we're having to put way more refrigerant than is required. Then then, what the system was designed for.

Okay, the components in the system aren't meant to handle that refrigerant. It just sounds like a walking disaster, okay, and I believe that I pretty much proved it with the numbers. You know I started with the factory charge of our 290, with the 134a put the hundred and thirteen grams in there, and it obviously wasn't doing anything. So then, I added refrigerant slowly trying to obtain the vital signs numbers that the system was performing with with the our 290.

Okay again, I kind of mentioned it in the video. But the reason why I did this is because I see an overwhelming what I consider to be a ridiculous amount of people saying that you can simply remove our 290 input 134a in the system. Okay - and I think I've disproved that now. I'm sure that someone like I said, can go ahead and put 134 a in and it might work half-ass, but it's not gon na work correctly and you're.

Setting yourself up for a major issue. I mean, I don't think anything's gon na explode, but certainly it's not working correctly. I imagine that you're gon na reduce the amount of compressor life. You know with my unit running as low as superheat as it is.

I'm sure that we're going to wash the oil out of that compressor and create some problems, we're gon na end up ruining the compressor eventually, okay, so for the customers sake, let's just go back with our 290. What belongs in the unit? Don't try to be a engineer. Okay. I really appreciate you guys taking the time to watch these couple things I want to mention number one.

I am part of a group of YouTube creators that has created a discord server on this particular discord server. It's just a community. It's a way to continue the conversation that goes on in the comments section and in the live chat section of a live stream, okay, but it doesn't have to be during a live stream. There's going to be a link in the top of the the video show notes for the particular discord server.

If you guys are interested in communicating with myself and the other creators, okay, there's a bunch of other creators that happen to be. You know my my fake internet friends, right that you know I communicate with on a regular. We all kind of set this up together, and it's just a way for us to make ourselves available to talk to people so check it out. If you just click the link, it'll download, the app and all that good, stuff and you'll be directed, you feel free to ask questions.

Also. I am starting a new YouTube channel. I've been mentioning it for a while. It's HVAC our tools, the link to that will be in the show notes of this video to really appreciate a follow.

I'm going to start uploading to that very soon. I'm sure this one, this video is gon na. You know raise a lot of questions, bring them on. Let's talk about it.

Send me questions emails comments. I do live streams Monday evenings at 5:00 p.m. Pacific time work for meeting so long as I can get off work I'll, be there to do the livestream and we'll talk about this stuff. Okay, alright yeah! I guess that's it we'll catch you guys on the next.

One: okay:.